What better way to spend a sunny spring afternoon than to participate in a pop-up celebrity chef challenge at your local Walmart parking lot, where the main ingredient is steak?

Last Tuesday, shoppers at the Walmart Supercenter # 1409 (10750 Westview Drive) had a lucky surprise when they pulled into the parking lot between 11 a.m. and 1 p.m.

Chefs Ronnie Killen of Killen's Steakhouse in Pearland and Bryan Caswell of Reef Houston were duking it out on the grill for the Walmart Choice Steak Challenge, serving up free samples of steak for public vote.

The main ingredient? Walmart's USDA Choice Premium Beef. Shoppers who are not completely satisfied with their steaks can bring back their receipts for a complete refund.

Killen came fully prepared to take on the challenge with a meat tenderizer and a Cryovac, which he used to infuse the meat with flavor. "I can't let a fish guy beat me at my own game," he was overheard saying, in reference to the facts that Caswell's restaurant is known for its fish and Caswell's Twitter handle is @wholefish.

What Caswell didn't have in gadgets, he made up for with charisma. Toward the end, he enticed voters with promises like "Free Astros tickets for whoever votes for blue," as well as some good-natured comments like "Mine's called better!"

Killen cut his steak into cubes.

Killen jokingly offered a free steak for every five votes, knowing that only one vote was allowed per person. In a show of bravado, he also pulled his phone out of his pocket and announced that he was making his reservation for New York well before the competition ended.

Tasters mentioned that the steaks tasted very different. Visually, they were distinct as well. Killen cut his steak into cubes, while Caswell cut his meat in strips, fajita-style. Tasters voted by dropping their favorite's toothpick -- Killen's was red, Caswell's was blue -- into a bin.

In the end, after all the toothpicks were counted, Killen was named the winner. Caswell graciously accepted his defeat, immediately shaking Killen's hand. He later tweeted a congratulatory message to Killen as well.

As the winner of the Walmart Choice Steak Challenge in Houston, Killen will advance to compete in the national cookout judged by pitmaster Chris Lilly in New York City on May 22.

The event was sponsored by Kingsford® Charcoal and Coca-Cola, and Houston was one of eight markets selected for the chef showdown. Killen will be competing with seven winners from Miami, Tampa, San Antonio, Dallas, St. Louise, Nashville and Atlanta.

Mai Pham is a contributing freelance food writer and food critic for the Houston Press whose adventurous palate has taken her from Argentina to Thailand and everywhere in between -- Peru, Spain, Hong Kong and more -- in pursuit of the most memorable bite. Her work appears in numerous outlets at the local, state and national level, where she is also a luxury travel correspondent for Forbes Travel Guide.